Question

if 3x+5y+4z=18,find the value of
(6-3x)^3 +(6-5y)^3+(6-4z)^3 - 3(6-3x)(6-5y)(6-4z)

Answer 1

Answer:

Step-by-step explanation:

3x+5y=9

=>3x=9-5y

=>x=(9-5y)/3

Substituting this value of x in 5x+3y=7

We get,  

5(9-5y)/3+3y=7

=>(5*9-5*5y)/3+3y-7=0

=>(45-25y) /3+3y-7=0

=>(45-25y+9y-21)/3=0

=>(24-16y) /3=0

=>24-16y=0

=>24=16y

=>y=24/16

=>y=3/2=1.5

Subtituting this value of y in x=(9-5y) /3

We get,  

x=(9-5*3/2)/3

=>x=(9-15/2)/3

=>x=(18-15)/6

=>x=3/6

=>x=1/2=0.5

Therefore, x=0.5, y=1.5